Single nucleotide polymorphisms (SNPs) of trace amine receptors

Abstract

Certain amines (tyramine, β-phenylethylamine, tryptamine, and octopamine) are found in trace amounts in peripheral tissues and the nervous system. Trace amine receptors (TARs) belong to the superfamily of G protein-coupled receptors and their signal transduction has been linked to cardiac complications. Here, we assessed for SNPs in the coding region of both TAR1 and TAR3 from 52 subjects [28 normotensive (NTs)/ 24 hypertensive (HT), 42 male/10 female, 29 Caucasian/23 African American, mean age 47±2]. We identified three TAR1 SNPs only in HTs: CGT->TGT, Arg25->Cys (2 HTs), CGC->TGC, Arg123->Cys (1 HT), and TGC->TGT, Cys267->Cys (4 HTs); while two TAR1 SNPs, ACA->ACC, Thr39->Thr (1 NT) and AGA->AGG, Arg314->Arg (1 NT), were found only in NTs. The sixth SNP of TAR1, GTA->GTG, Val290->Val, was detected in 6 NTs and 2 HTs. We also identified several SNPs in TAR3: AAC->AAT, Asn25->Asn (4 NTs and 4 HTs), TTT->TAT, Phe69->Tyr (1 HT), TCC->TCT, Ser114->Ser (2 NTs and 3 HTs), GCA->ACA, Ala278->Thr (1 NT and 2 HTs), and TCG->TTG, Ser335->Leu (1 NT and 2 HTs). The only SNP with high allelic frequency (22.1%) in this study was a premature stop codon in TAR3, AAA->TAA, Lys61->stop, found in 13 NTs and 6 HTs. These results indicate that although both TARs are polymorphic, most SNPs, other than TAR3 AAA ->TAA, are not common. Larger sample size is needed to confirm and extend these findings but the data suggest that there are differences in expression of TAR1 and TAR3 SNPs between normotensive and hypertensive subjects. (Supported by grants from NIH).